Tropical Discovery (Denver Zoo)

Denver Zoo dates its beginnings to 1896, when a black bear given to the city's mayor became the first resident of a collection in City Park. The master plan drawn up in 1959 ended with the construction of an aquarium; that final step was only realised more than three decades later, and in broader form, when Tropical Discovery opened in 1993.

The building cost 11.5 million dollars and was designed by the Denver architecture practice Anderson Mason Dale. Its opening was a turning point for the zoo: it doubled both the number of species and the number of animals on display, and around 90 per cent of the animals it introduced had never been exhibited at the zoo before. Since then the hall has served as the public aquarium and reptile house for the whole zoo. Its displays have changed over the years, and the zoo now highlights a new habitat for its sloths.

Tropical Discovery is laid out as an indoor tropical garden crowned by glass pyramids. The glazed roof gives the building the high, skylit ceilings described by the zoo and allows dense planting to grow under cover around the animal displays. Anderson Mason Dale's scheme gathered aquarium and reptile-house functions beneath a single roof, expanding what the 1959 plan had conceived as a plain aquarium.

The route passes through contrasting settings: jungle, coral reef, pools and terrariums, along with a bat cave. The height available beneath the pyramids is put to use for tree-dwelling species, with a sloth tree about 22 feet, or roughly 6.7 metres, tall. These settings follow one another beneath the same glazed roof.

According to Wikipedia, the hall holds more than 250 plant species, which form the backdrop of its different zones. The zoo lists nearly 300 animal species and some 1,800 individual animals there, spread between aquatic and land habitats.

Tanks and pools show sea stars and reef fish, amphibians such as the Lake Titicaca frog and various tree frogs, and many reptiles, among them the Komodo dragon, the green anaconda and other snakes. Linne's two-toed sloth has its own tree, and a cave is set aside for bats. The best-known resident is Daphne, a Siamese crocodile that the zoo describes as its oldest animal, aged 64 according to its website.

Tropical Discovery is visited as part of a day at Denver Zoo in City Park. Fully enclosed, the hall makes a welcome refuge during the Colorado winter or in poor weather; allow at least an hour for the reef and aquatic zones, the terrariums, the bat cave and the sloth habitat.

A visit pairs easily with the Boettcher Memorial Conservatory, the large tropical glasshouse of Denver Botanic Gardens, a little over two kilometres to the south-west and also featured in this atlas.